The invention relates to a tool-exchanging device and, in particular, to the suction crossbar-exchanging device in press lines, multiple-die presses for large parts or he like.
In the case of a press, a press line or a multiple-die press for large parts, transfer devices are provided for transporting parts. For the newer developments of the German patent 100 09 574, the transporting process proceeds through separate transporting systems assigned to each press or press stage. These devices, which can be controlled or regulated individually, carry away the workpiece, which is to be shaped, from one tool step and supply it to the subsequent tool stage. The transporting system is constructed as a sort of pivoted arm. By integrating a large number of degrees of freedom or movement axes, it is possible, during the transporting movement, to carry out a change in the position of the workpiece, which is optimally adapted to the shaping process. This also makes it possible to do without interim storage areas and, with that, to reduce significantly the distances between tool stages. The total length of the press installation is reduced clearly by this measure.
Likewise, a completely automatic tool-exchanging system, including an exchanging system for the parts-specific accessories of the transporting system, is known as state of the art. An appropriate representation is given in the German patent 43 09 661. When tools are exchanged, the transverse lifting beams or suction crossarms, carrying the workpieces are pegged out on connecting pins. These connecting pins are fastened to the sliding table. With that, the transverse lifting beams can be moved out of the press room. During the production phase, the connecting pins are swiveled laterally above the upper edge of the sliding table into an approximately horizontal position. In order to avoid a collision with the transporting system, it is necessary to carry out this swiveling of the connecting pins outside of the area in which the workpiece is transported
The inadequate accessibility of the press is a disadvantage of this and other known systems. Due to the space-saving construction resulting from the newer transfer systems, there is very little access to the free spaces between the sliding table with tool and the press pedestal. When there are operational malfunctions during production, access to the press area must be possible. Due to the swiveled connecting pins, disposed at a greater height, this access is impeded greatly. The solution, disclosed in the British patent 2,199,781, with cantilevers mounted laterally in the outer regions of the sliding table and with a pivotable removing device for suction crossarms, is likewise advantageous.
It is an object of the invention to avoid the above-described disadvantages of the state of the art and to configure a tool-exchanging device and, in particular, an exchanging device for the parts-specific accessories in such a manner, that accessibility to the press area is not impeded thereby. The exchanging device shall be relatively inexpensive and constructed in the form of a modular system in a space-saving manner.
Starting out from a transporting system and a tool-exchanging device of the type described above, this objective is accomplished pursuant to the invention by the distinguishing features.
Due to the inventive solution, the objective posed can be accomplished and the disadvantages of the state of the art avoided by the application of the individual distinguishing features as well as by their inventive combination. Moreover, the invention is based on the concept of disposing the exchanging device for the parts-specific accessories and configuring the course of motion in such a manner, that any impediment to the accessibility of the press area is avoided.
In a compact construction, the exchanging device usually consists of two units, which are mounted one each at the end regions of the sliding table. Two types of movement are proposed for moving the device into the exchanging position:
1. A swiveling motion totaling approximately 90xc2x0
2. A vertical, linear motion
The pivot drive makes different positions of the exchanging device possible. These may, for example, be the following:
horizontal position during the production phase
position inclined at the required angle for the transfer of the suction crossarm to the press and also for exchanging the suction crossarm outside of the press. This position is also advantageous for exchanging tools.
perpendicular position as exit or entry position or also, in an alternative variation, for transferring the suction crossarm in the press.
For one embodiment, a driven-in parked position and a driven-out exchanging position are provided by means of a linear driving mechanism.
The exchanging device is equipped with a mounting and optionally with a clamping system for the suction crossarm. In order to avoid interfering edges due to the suction spiders fastened on the suction crossarm, the latter may have to be able to rotate about its axis. This rotating device may be a component either of the exchanging device or of the transporting system.
During the exchange of tools, the transporting system with the suction crossarm in the pedestal region is in a parked position. By a downward movement of the ram, the upper tool is moved onto the lower tool and the jig is loosened. After that, the ram moves up and the tool-exchanging device moves into the exchanging position in order to take over the suction crossarm. Two variations, for example, are possible during the swiveling:
1. The tool-exchanging device is swiveled so far, that the suction crossarm can be transferred into the parked position of the transporting system. At the same time, the mounting and clamping system of the exchanging device of the suction crossarm is taken over in a precise position and then uncoupled from the transporting system. The uncoupling is also required for the energy-supplying pipelines and the vacuum system. After the takeover, the tool-exchanging device swivels into a vertical position and, at the same time, rotates the suction crossarm in such a manner about its axis, that the suction spiders assume a position required for the trouble-free moving out.
2. In the case of the alternative variation, the tool-exchanging device swivels by about 90xc2x0 from the horizontal position into the vertical position. The transporting system swivels from the parked position so far in the direction of the tool-exchanging device, that a transfer of the suction crossarm is possible. In addition, the transporting system rotates the suction crossarm by an amount, which, in turn, also makes the problem-free moving out of the suction spiders possible. In the case of this solution, the suction crossarm clamping system in the tool-exchanging device may optionally be omitted.
If the exchanging device is driven by means of a linear drive, the course of the movement of the transporting system is as described under 2. In order to reduce the necessary moving-out path of the exchanging device, the transporting system additionally moves into a lower position, which is slightly larger than half the width of the suction spider. Depending on the construction and position of the mounting, the suction crossarm can be transferred to the exchanging device by a vertical as well as by a horizontal movement.
The invention is particularly advantageous if the tool-exchanging device represents a form of modular system. By the proposed solutions, an advantageously priced and very compact construction is achieved.
The driving mechanism for the swiveling motion as well as the linear drive are attached in a stationary manner at the sliding table. This is advantageous for reducing the weights, which have to be accelerated, as well as for connecting the electrical leads.
Changing the setup outside of the press is also facilitated by the invention. The clamping sites of the lower tool are accessible without any obstruction. An optimum exchanging position can be achieved by swiveling the exchanging device with the suction crossarm through any angle. Likewise, there are no interfering regions for the attachment and function of the transporting ropes, which are required for lifting or placing down the tools by means of a crane.